Summon, formerly known as InstantCab, is a San Francisco-based on-demand transportation app that connects riders with vetted taxi and personal car drivers. The app requires users to enter their credit or debit card information, and all fares and tips are paid through this card. Summon only charges riders after they have been dropped off at their destination. The idea for Summon came about when founder Aarjav missed an international flight due to the lateness of his transportation. The company aims to provide fair pricing for riders and transparent policies for drivers.